Steam plant



H. GLEICHMANN STEAM PLANT Original Filed Aug. l5. 1928 April 1s, 1933.

ik N w Patented Apr. /18, 1933 .UNITED STATES HANS GLEIGHMANN, orFALKENHAIN NEAR srANnAU, GERMANY, AssreNon 'ro SIEMENS-SCHUCKERTWERKEAKTIENGESELLSCHAFT, OF GERMANY, A CORPORATION OF GERMANYBERLIN-SIEMENSSTADT,

STEAM `PLANT Original application led August 15, 1928, Serial No.299,801,7.and in Germany June 27, 1928. Divided and this application ledJanuary 4, 1930.V ySerial No. 418,511. 1'

In plants of this character, especially in cases where highv steampressures and temperatures are employed, the feed water purity for thehigh pressure steam generator is by far more important, especially incases of purely tubular steam generators, than it was heretofore withthe ordinary low pressure and low temperaturel drum boiler, because intubular boilers the impuritiesare more likely to impair the eiiiciencyand correct operation of the` boiler. These conditions have suggested tothe art the division of the steam generation for the high and lowpressure sections of the prime mover into two distinct stages, so thatthe steam discharged from the high pressure prime mover is not directlydelivered into the low pressure section or sections of `the prime moversystem, from which latter the condensate might be returned to the steamgenerator in impure condition. .Between the high and low pressuresections of the prime mover system is then interposed a steamtransformer in which the temperature of thehigh pressure steamdischarged from the high pressure prime mover is utilized for generatinglowpressure steam for the low pressure section of the prime mover systemwhich latter constitutes thereby an entirely independent mediumcirculating system. This avoids the contamination of the high pressuresteam generator water by the low pressure steam consumers, and permitsthe return of the high pressure steam condensate directly to the highpressure steam generator. The thermodynamic losses which are suffered ina system of this character are by far outweighed by the great advantagesgained in the pureness of the feed water for the high pressure system,and besides by the judicious employment of mixing condensers in the lowVpressure steam system, instead of surface condensers, `thermal lossessuffered in the high pressure system are practically retrieved in thelow pressure system. This is true, because in mixingconden'sers Vtheeiiiciency and the vacuum are greater than in surface condensers, and inaddition the first cost and maintenance cost of a mixingcondenser,whichpontains only simple sprays, are both considerably l llower than those of surface condensers.

A steam generating plant of this character and involving theabove-mentioned general ideas is disclosed in my copending application,Serial No.4 299,801, led August 15, 1928, of whichy the ypresentapplication is adivision.

This presentapplication deals'with some particular improvements onthischaracter of plant, based yon the following consideration.

The interposition of va steam transformer or heat exchanger alonebetween the high pressure and low pressure sections of the prime moversystem, such as is suggested in the aforementioned yparent application,does not complete the measures necessary for eiiiciently solving thefeed water problem for-high pressure and high temperature steam'generators. In particular ,with the use ofpurely tubular steamgenerators, it must be taken into account that the feed water vcontainsdissolved minerals whichareapt to vcrystallize during the steamvgeneration, .and the steam `is apt to carry'these crystals along anddeposit them in the generator;` tubes where theiraccumulation is likelyVto, danfeo gerously reduce the cross-section 0fv the l tubes, and insome cases isapt tolclogthem altogether. Such crystals are alsollikely-to cause considerable wear of the turbine buckets.

The above disadvantages are overcomeaccording to they present inventionby interposing :into Vthe high pressure circulating system, and directlyahead of the steam transformer, a steam purifier, which constitutes apurifying chamber filled' with a suitable Washing liquid, and inwhich'th-e steam exhausted from the high pressure prime mover .iscondensed and regenerated on the surface of the liquid before it entersthe steam heat exchanger. This washing process dissolves thecrystallized 'mineral matter which 'might i be contained -in the steam,so that it can be drained ofi' from the washing chamber, and therebyremoved from lcirculation system.

If reciprocating prime movers are used-in the highpressure section ofthe prime mover system, besides a L mechanical or, chemical sump 13.

Referring tothe drawing, 1 represents the high pressure high temperaturesteam gen` erator which delivers by way of a steam main 3 steam to theprime mover lV which, in .this

case, has the form of'a reciprocating piston machine. The steam 'isdischarged from the low pressure stage 76 of prime mover 4, and afterpassing through an oil .separator 78 is discharged through a conduit 84into a' steam washing devicel82 of the steam regeneration type. Thisdevice functions by condensing the steam supplied to it in the washingliquid, and by regeneratingit on thesurface of the liquid. The steamthus regenerated is free from all impurities, including'mineral salts,which the generator .steam might have carried along, and which remaindissolved in the washing liquid. As awashing liquid 'the samekind ofliquid is used as the one from which the vapor is generated 'in theylhigh pressure system; inthe present case ofy high pressure steamgeneration, water would be used as a washing liquid. Water as a steamWashing liquid is well knownin theart. The'puriiied steam passes fromthis washing chamber by way of a conduit 85 into the steaml heatexchanger or steam transformer 83 inwhich the heat exchanger 12 isdisposed "through which the high pressure high temperature exhaust steampasses, and

whichheats the water contained inthe steam transformer, therebygenerating low prese sure steam.v

' Preferably the steam washing chamber is made a part of the steamtransformer fby dividing the transformer drum by means ofa partitionwall 81 into two compartments,

fone of which forms the steam washing chamber, and the other the steamtransformer chamber. c s

v The water from which the lowvpressure steam is generated in the steamtransformer is supplied fromla sump 13 through a. pump 14, and by way offeedv water heaters 25,

into the steam transformer, and the second-Y ary steam( generated invthesteam transformer is supplied by way of secondary main 21 to a lowpressure steam consumer which is in this' case represented `by a lovvpressure turb1ne48. The exhaust steam from `this turbine isc'ondensed'in'a mixing condenser 52 which is supplied'fwith cold water through pump53, the condensate from this condenser flowing by way ofv dischargeypipe 54 into the The condensate discharged by the heatexi changer 12 ofthe'steam transformer Vflows generating systemaccording to my inthroughthe pipe 17 into the feed water heat' er 25 aforementioned, and thencethrough pipe 26 into the sump 18 from which it is delivered by feedYpump 19 into'the high pressure steam generator 1, thereby establishingan entirely separate circulation independent .of the klow pressuresteamA generating circuit. y

Aside from heating the feed water for the steam transformer .by .'means.of. ftheY condensate discharged from the heat exchanger 12, this feedwater is further heated to a suitable higher temperature by means ofinterstage steam tapped between the.' stages L75 and. 76of thehighpressure prime mover 4;, which after passing through an oilseparato'r "86 first serves for sup-erheating. the

secondary steam generated in the steam transformer through a coil 42disposed in the dome 68 of the steam transformer. From coil 12 the steampasses through *pipev 24 into the feed water heater 4 5, whence itisdischarged s through a pipej87vby way of acontrol valve 88 'intothe'steam washing chamber.V 'A check valve 100is provided near the steamentrance intoth-e washing chamber, in order to prevent the washingliquid from entering feed water heater 45 in case'the pressure in theWashing chamber exceeds that in the water heater 41:5.`

Aside Vfrom feeding "the steamwashing chamber with exhaust steam"'fromprime mover 4, an additional supply of steam may be delivered :directlyfrom mainf by 'Way' of a control'valve 90 which is controlled by apressure responsive device 92 connected t0 main 3 such that -asthe`pressure in steam main increases valve opens further and delivers moresteam into the steaml washer and steam transformer. Y I

For contr-olling the feed' water supply to steam transformer 83, a valve32 is provided in the feed' water line between pump 14:V and feed water'heater 25,y which valve is controlled by fa `pressure responsive -device34; responding to pressure variations in the sec-V ondary steam main 2l,so that when theV pressure in the latter decreases, more feed water issupplied to the transformer and when it increases, the reverse occurs.

',Likewise, the pressurev variations in sectrolling the fuel supply tosteamv generator -TIO 1 by means of'pressure responsive device 38connected lto the secondary' main and controlling fuel supply Valve,104.- such-that when the secondary steam pressure decreases the fuelsupply increases and when the pressure increases the fuel valve isactuated thereverse way. Y, v 'l lclaima` A high and lowy pressure vaporpower yplant having a high pressure circuit.' for the operating mediumincluding a high pressure vapor I generator, a high pressure prime moversup liedfwith vapor from the/generator, a

IT15 ondary steam main 21 are utilized for con- Y vapor transformer ofthe indirect heating type connected at its prim-ary side to the exhaustside of said high pressure prime mover, and means for returning thecondensate from the primary side of the vapor transformer to saidgenerator, the low pressure medium circuit including the secondary sideof said vapor transformer and a lon7 pressure vapor consumer, the highpressure 10 medium circuit including a vapor Washer of the direct vaporregeneration type containing a Washing liquid of the same kind as theliquid from which the high pressure vapor is generated, said Washerbeing interposed l5 between said prime mover exhaust and the primaryside of said transformer, whereby through the regeneration of vapor fromsaid Washing liquid purified vapor is delivered to said transformer andpurified condensate is returned to said generator.

HANS GLEICHMANN.

